Why am I unable to see the screen during calls on my Moto 1x 2nd gen?

Screen is black during calls and for about 10 seconds after call auto disconnects. Unable to end calls or bring up keypad for in call menus. Has been a problem from day one. Never dropped or in any way damaged phone. Is problem likely hardware and I need to return it or is it software and there is a "fix" I can download?

Answering my own question ... it turns out there were lots more options in the input zone settings hidden down below. There are options for turning off the moving zone or setting it up to move only after a certain portion of the zone is written in. Thanks!